/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jclouds.rest.suppliers;

import com.google.common.annotations.Beta;
import com.google.common.base.Optional;

/**
 * Callback that gets called every time the supplier loads new values.
 */
@Beta
public interface ValueLoadedCallback<V> {
   
   void valueLoaded(Optional<V> value);

   /** The default implementation does nothing */
   public static class NoOpCallback<V> implements ValueLoadedCallback<V> {
      @Override
      public void valueLoaded(Optional<V> value) {
         // Do nothing
      }
   }
}
